Re: UTF-8 and case-insensitivity

tridge
2004-02-18T23:11:33Z

Linus,

> Why do you focus on linear directory scans?

Because a large number of file operations are on filenames that don't
exist. I have to *prove* they don't exist. That includes:

* every file create. I have to prove there wasn't an existing file
under a different case combination.

* every rename. Again, I have to prove that the destination name
doesn't exist.

* every open of a non-existant name (*very* common, its what MS
office does all the time).

etc etc.

If I had a single function that could quickly tell me that a file does
not exist in any case combination then I would be much better off.

> They simply do not happen under any reasonable IO patterns. You look up
> names under the same name that they are on the disk. So the _only_ thing
> that should matter is the exact match.

nope, see above. The most common pattern of accesses involves doing a
full directory scan on every access.

> Sure, I can imaging that MS would make some benchmark to show that case,
> but at that point I just don't care.

It's not just "some benchmark". It's the normal use case.

Cheers, Tridge